A future classic from one of the biggest brands historically. Universal Geneve Dual time with the smartest complication for displaying a second time zone . The model launched at Basel in 1997.

The blue hour hand is advanced stepwise by the button at 8, then shadows the regular hour hand and shows the second time zone all the time. Between 18-06 in the second time zone the dot at 7:30 is blue for "night" and at 06-18 , it turns yellow for " day " . Very smooth!!! I think another brand called Patek Philip or something has added a similar complication lately...
If not needed the second hour hand is completely hidden behind the regular one.